Title:           [C#] Wallpaper.cs
Author:          Erb1tux
Pastebin link:   http://pastebin.com/ykqbRKpn
First Edit:      Saturday 13th of September 2014 05:23:27 PM CDT
Last Edit:       Saturday 13th of September 2014 05:23:27 PM CDT

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
 
namespace Background_Changer
{
    public sealed class Wallpaper
    {
        Wallpaper() { }
 
        const int SPI_SETDESKWALLPAPER = 20;
        const int SPIF_UPDATEINIFILE = 0x01;
        const int SPIF_SENDWININICHANGE = 0x02;
 
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);
 
        public enum Style : int
        {
            Tiled,
            Centered,
            Stretched
        }
 
        public static void Set(Uri uri, Style style)
        {
            System.IO.Stream s = new System.Net.WebClient().OpenRead(uri.ToString());
 
            System.Drawing.Image img = System.Drawing.Image.FromStream(s);
            string tempPath = Path.Combine(Path.GetTempPath(), "wallpaper.bmp");
            img.Save(tempPath, System.Drawing.Imaging.ImageFormat.Bmp);
 
            RegistryKey key = Registry.CurrentUser.OpenSubKey(@"Control Panel\Desktop", true);
            if (style == Style.Stretched)
            {
                key.SetValue(@"WallpaperStyle", 2.ToString());
                key.SetValue(@"TileWallpaper", 0.ToString());
            }
 
            if (style == Style.Centered)
            {
                key.SetValue(@"WallpaperStyle", 1.ToString());
                key.SetValue(@"TileWallpaper", 0.ToString());
            }
 
            if (style == Style.Tiled)
            {
                key.SetValue(@"WallpaperStyle", 1.ToString());
                key.SetValue(@"TileWallpaper", 1.ToString());
            }
 
            SystemParametersInfo(SPI_SETDESKWALLPAPER,
                0,
                tempPath,
                SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);
 
            s.Dispose();
            img.Dispose();
            key.Dispose();
        }
        public static string GetCurrentWallpaper()
        {
            // The current wallpaper path is stored in the registry at HKEY_CURRENT_USER\\Control Panel\\Desktop\\WallPaper
 
            RegistryKey rkWallPaper = Registry.CurrentUser.OpenSubKey("Control Panel\\Desktop", false);
            string WallpaperPath = rkWallPaper.GetValue("WallPaper").ToString();
            rkWallPaper.Close();
 
            // Return the current wallpaper path
            return WallpaperPath;
        }
 
    }
}